Re: [PATCH v2] s390/vfio-ap: fix memory leak in mdev remove callback

From: Jason Gunthorpe
Date: Wed May 12 2021 - 08:41:47 EST


On Mon, May 10, 2021 at 05:48:37PM -0400, Tony Krowiak wrote:
> The mdev remove callback for the vfio_ap device driver bails out with
> -EBUSY if the mdev is in use by a KVM guest. The intended purpose was
> to prevent the mdev from being removed while in use; however, returning a
> non-zero rc does not prevent removal. This could result in a memory leak
> of the resources allocated when the mdev was created. In addition, the
> KVM guest will still have access to the AP devices assigned to the mdev
> even though the mdev no longer exists.
>
> To prevent this scenario, cleanup will be done - including unplugging the
> AP adapters, domains and control domains - regardless of whether the mdev
> is in use by a KVM guest or not.
>
> Fixes: 258287c994de ("s390: vfio-ap: implement mediated device open callback")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxx>
> ---
> drivers/s390/crypto/vfio_ap_ops.c | 13 ++-----------
> 1 file changed, 2 insertions(+), 11 deletions(-)

Can you please ensure this goes to a -rc branch or through Alex's
tree?

Thanks,
Jason